title: Perturbing the action observation network during perception and categorization of actions' goals and grips: state-dependency and virtual lesion TMS effects.
abstract: Watching others grasping and using objects activates an action observation network (AON), including inferior frontal (IFC), anterior intraparietal (AIP), and somatosensory cortices (S1). Yet, causal evidence of the differential involvement of such AON sensorimotor nodes in representing high- and low-level action components (i.e., end-goals and grip type) is meager. To address this issue, we used transcranial magnetic stimulation-adaptation (TMS-A) during 2 novel action perception tasks. Participants were shown adapting movies displaying a demonstrator performing goal-directed actions with a tool, using either power or precision grips. They were then asked to match the end-goal (Goal-recognition task) or the grip (Grip-recognition task) of actions shown in test pictures to the adapting movies. TMS was administered over IFC, AIP, or S1 during presentation of test pictures. Virtual lesion-like effects were found in the Grip-recognition task where IFC stimulation induced a general performance decrease, suggesting a critical role of IFC in perceiving grips. In the Goal-recognition task, IFC and S1 stimulation differently affected the processing of "adapted" and "nonadapted" goals. These "state-dependent" effects suggest that the overall goal of seen actions is encoded into functionally distinct and spatially overlapping neural populations in IFC-S1 and such encoding is critical for recognizing and understanding end-goals.
authors.affiliation: Department of Psychology, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, 69676 Bron cedex, France.
authors.forename: Pierre O
authors.initials: PO
authors.lastname: Jacquet
authors.affiliation: Department of Psychology, Alma Mater Studiorum, University of Bologna, 40127 Bologna, Italy Centro studi e ricerche in Neuroscienze Cognitive, Campus di Cesena, University of Bologna, 47521 Cesena, Italy Istituto di Ricovero e Cura a Carattere Scientifico Fondazione Santa Lucia, 00179 Roma, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Avenanti
mesh_terms: D000328:Adult; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006040:Goals; D018737:Hand Strength; D006801:Humans; D008297:Male; D009043:Motor Activity; D009415:Nerve Net / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: action observation network; action perception; somatosensory cortex; state dependency; transcranial magnetic stimulation; virtual lesion